diff --git a/postinstall.md b/postinstall.md
index 369220d3..d1e224f5 100644
--- a/postinstall.md
+++ b/postinstall.md
@@ -14,12 +14,15 @@ The step called "**post-installation**" is actually the initial configuration of
 
 *<p class="text-muted">Preview of the command-line post-installation</p>*
 
----
+<br>
+<br>
+
+<div class="alert alert-warning">
+**Attention**: The post-installation may break your system if you interrupt it, be aware.
+</div>
 
 Two configuration parameters will be asked: the **main domain name** and the **administration password**.
 
-**Attention**: The post-installation may break your system if you interrupt it, be aware.
-
 ### Main domain
 
 This is the first domain name linked to your YunoHost server, but also the one which will be used by your server's users to access the **authentication portal**. It will thus be **visible by everyone**, choose it wisely.